1. Field of the Invention
The invention relates to communication networks. In particular, the invention relates to providing roaming status information for controlling services in a packet data based communication network in a novel and improved way.
2. Description of the Related Art
Recently also mobile communication networks have started to support transmission of packet switched data or packet data in addition to traditional circuit switched data transmission.
An example of a technique allowing packet data transmission for mobile communication networks is General Packet Radio Service (GPRS). GPRS is designed to support e.g. digital mobile telecommunication networks based on the Global System for Mobile Communications (GSM) standard. However, GPRS is not restricted to only GSM networks but may support for example 3rd Generation Partnership Project (3GPP) based digital mobile telecommunication networks. Other examples of packet data based mobile communication networks are Wireless Local Area Network (WLAN) and Code Division Multiple Access (CDMA) based mobile communication networks.
A GPRS enabled mobile communication network comprises supplementary network elements or nodes in addition to existing network elements. These include a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN). An SGSN typically delivers packets to and from GPRS enabled terminal devices within its service area. A GGSN is typically used as an interface to external IP networks such as the Internet, other mobile service providers' GPRS services, or enterprise intranets.
The introduction of packet data based mobile communication networks has naturally resulted in various value-added subscriber services being provided for these packet data based mobile communication networks. Examples of such subscriber services are packet data based voice, email, content downloading, browsing, streaming and rich calls. Furthermore, packet data based mobile communication networks offer network services to support the usage of subscriber services. Such network services include e.g. rerouting, barring, accounting, content proxy services, content blocking services, firewall services, virus scanning services, performance enhancement proxy services, Virtual Private Network (VPN) services, various Quality of Service (QoS) related services and various charging related services for both online and offline charging.
A recent trend is to provide the various subscriber services for packet data based mobile communication networks in a subscriber specific manner. For example, based on definitions in a subscription profile of a given subscriber, it may be determined whether the subscriber will be allowed a given subscriber service out of a plurality of subscriber services. Furthermore, if a given subscriber service is allowed, a Quality of Service class and bit rate(s) for the subscriber service may be determined based on the subscription profile. Furthermore, charging for the subscriber service may depend on data in the subscription profile. The subscription profile typically comprises a set of definitions or parameters defining which subscriber services and how are to be provided to the subscriber. Typically, when a subscriber subscribes to a new subscriber service or e.g. updates an already subscribed subscriber service, a network operator updates the subscription profile correspondingly.
However, there is one parameter which today cannot be taken into account when determining which subscriber services and how are to be provided to a subscriber of packet data based mobile communication network. That parameter is roaming status of a subscriber. As is known in the art, in the context of mobile communication networks, when a subscriber connects via a service area that is managed by an operator other than the one with whom the subscriber originally registered with, the subscriber is said to be ‘roaming’. A typical example of a subscriber roaming is when the subscriber is in a foreign country. In contrast, when the subscriber connects via a service area that is managed by the operator with whom the subscriber originally registered with, the subscriber is said to be at ‘home’.
Obviously, it would be highly desirable to be able to take into account roaming status of a subscriber at a given moment when determining which subscriber services and how are to be provided to the subscriber at that moment. For example, different subscriber services may be available when roaming or at home, different charging and/or QoS might be applied on a subscriber service depending on whether the subscriber is at home or roaming.
Yet, today this is not possible for packet data based mobile communication networks since the existing packet data based mobile communication networks do not provide a mechanism that would allow providing roaming status information for service control.
Therefore, the object of the present invention is to alleviate the problems described above and to introduce a mechanism that allows providing roaming status information for service control.